282 lines
6.5 KiB
C
282 lines
6.5 KiB
C
/* $NetBSD: pf.c,v 1.3 1997/03/25 03:07:27 thorpej Exp $ */
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/*
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* Copyright (c) 1993-95 Mats O Jansson. All rights reserved.
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is partly derived from rarpd.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Mats O Jansson.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef LINT
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static char rcsid[] = "$NetBSD: pf.c,v 1.3 1997/03/25 03:07:27 thorpej Exp $";
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#endif
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#include <stdio.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/time.h>
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#include <sys/ioctl.h>
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#include <sys/file.h>
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#include <sys/socket.h>
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#include <sys/uio.h>
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#include <net/if.h>
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#include <net/bpf.h>
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#include <sys/errno.h>
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#include <netinet/in.h>
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#include <netinet/if_inarp.h>
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#include <netdb.h>
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#include <ctype.h>
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#include <strings.h>
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#include <syslog.h>
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#include <varargs.h>
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#include "common/mopdef.h"
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/*
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* Variables
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*/
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extern int errno;
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extern int promisc;
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/*
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* Return information to device.c how to open device.
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* In this case the driver can handle both Ethernet type II and
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* IEEE 802.3 frames (SNAP) in a single pfOpen.
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*/
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int
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pfTrans(interface)
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char *interface;
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{
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return TRANS_ETHER+TRANS_8023+TRANS_AND;
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}
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/*
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* Open and initialize packet filter.
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*/
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int
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pfInit(interface, mode, protocol, typ)
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char *interface;
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u_short protocol;
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int typ, mode;
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{
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int fd;
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int n = 0;
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char device[sizeof "/dev/bpf000"];
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struct ifreq ifr;
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u_int dlt;
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int immediate;
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static struct bpf_insn insns[] = {
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BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12),
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BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 4, 0),
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BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20),
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BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 0, 3),
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BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 14),
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BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xaaaa, 0, 1),
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BPF_STMT(BPF_RET | BPF_K, 1520),
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BPF_STMT(BPF_RET | BPF_K, 0),
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};
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static struct bpf_program filter = {
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sizeof insns / sizeof(insns[0]),
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insns
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};
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/* Go through all the minors and find one that isn't in use. */
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do {
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(void) sprintf(device, "/dev/bpf%d", n++);
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fd = open(device, mode);
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} while (fd < 0 && errno == EBUSY);
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if (fd < 0) {
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syslog(LOG_ERR,"pfInit: open bpf %m");
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return(-1);
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}
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/* Set immediate mode so packets are processed as they arrive. */
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immediate = 1;
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if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) {
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syslog(LOG_ERR,"pfInit: BIOCIMMEDIATE: %m");
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return(-1);
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}
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(void) strncpy(ifr.ifr_name, interface, sizeof ifr.ifr_name);
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if (ioctl(fd, BIOCSETIF, (caddr_t) & ifr) < 0) {
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syslog(LOG_ERR,"pfInit: BIOCSETIF: %m");
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return(-1);
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}
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/* Check that the data link layer is an Ethernet; this code won't work
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* with anything else. */
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if (ioctl(fd, BIOCGDLT, (caddr_t) & dlt) < 0) {
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syslog(LOG_ERR,"pfInit: BIOCGDLT: %m");
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return(-1);
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}
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if (dlt != DLT_EN10MB) {
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syslog(LOG_ERR,"pfInit: %s is not ethernet", device);
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return(-1);
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}
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if (promisc) {
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/* Set promiscuous mode. */
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if (ioctl(fd, BIOCPROMISC, (caddr_t)0) < 0) {
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syslog(LOG_ERR,"pfInit: BIOCPROMISC: %m");
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return(-1);
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}
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}
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/* Set filter program. */
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insns[1].k = protocol;
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insns[3].k = protocol;
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if (ioctl(fd, BIOCSETF, (caddr_t) & filter) < 0) {
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syslog(LOG_ERR,"pfInit: BIOCSETF: %m");
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return(-1);
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}
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return(fd);
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}
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/*
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* Add a Multicast address to the interface
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*/
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int
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pfAddMulti(s, interface, addr)
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int s;
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char *interface, *addr;
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{
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struct ifreq ifr;
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int fd;
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strcpy(ifr.ifr_name, interface);
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ifr.ifr_addr.sa_family = AF_UNSPEC;
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bcopy(addr, ifr.ifr_addr.sa_data, 6);
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/*
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* open a socket, temporarily, to use for SIOC* ioctls
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*
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*/
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if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
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syslog(LOG_ERR, "pfAddMulti: socket: %m");
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return(-1);
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}
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if (ioctl(fd, SIOCADDMULTI, (caddr_t)&ifr) < 0) {
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syslog(LOG_ERR, "pfAddMulti: SIOCADDMULTI: %m");
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close(fd);
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return(-1);
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}
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close(fd);
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return(0);
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}
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/*
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* Delete a Multicast address from the interface
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*/
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int
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pfDelMulti(s, interface, addr)
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int s;
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char *interface, *addr;
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{
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struct ifreq ifr;
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int fd;
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strcpy(ifr.ifr_name, interface);
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ifr.ifr_addr.sa_family = AF_UNSPEC;
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bcopy(addr, ifr.ifr_addr.sa_data, 6);
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/*
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* open a socket, temporarily, to use for SIOC* ioctls
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*
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*/
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if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
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syslog(LOG_ERR, "pfDelMulti: socket: %m");
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return(-1);
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}
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if (ioctl(fd, SIOCDELMULTI, (caddr_t)&ifr) < 0) {
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syslog(LOG_ERR, "pfAddMulti: SIOCDELMULTI: %m");
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close(fd);
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return(-1);
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}
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close(fd);
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return(0);
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}
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/*
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* read a packet
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*/
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int
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pfRead(fd, buf, len)
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int fd, len;
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u_char *buf;
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{
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return(read(fd, buf, len));
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}
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/*
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* write a packet
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*/
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int
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pfWrite(fd, buf, len, trans)
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int fd, len, trans;
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u_char *buf;
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{
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struct iovec iov[2];
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switch (trans) {
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case TRANS_8023:
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iov[0].iov_base = (caddr_t)buf;
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iov[0].iov_len = 22;
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iov[1].iov_base = (caddr_t)buf+22;
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iov[1].iov_len = len-22;
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break;
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default:
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iov[0].iov_base = (caddr_t)buf;
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iov[0].iov_len = 14;
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iov[1].iov_base = (caddr_t)buf+14;
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iov[1].iov_len = len-14;
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break;
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}
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if (writev(fd, iov, 2) == len)
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return(len);
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return(-1);
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}
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